• Animal cells and systems
• /
• v.8 no.2
• /
• pp.125-133
• /
• 2004

We have extended our previous work that cross-linking CD4 molecules using specific MAb induced antigen nonspecific, MHC unrestricted killing of virally infected target cells by CD$4^+$We have extended our previous work that cross-linking CD$4^+$ molecules using specific MAb induced antigen nonspecific, MHC unrestricted killing of virally infected target cells by CD$4^+$ T cells. The killing activity of antibody activated CD$4^+$T cells was completely blocked by herbimycin A, a protein tyrosine kinase (PTK) inhibitor, but not by bisindolylamaleimide, a protein kinase C (PKC) inhibitor. Herbimycin A treated human or bovine peripheral blood CD$4^+$T cells lacked PTK activity and failed to kill virally infected target cells even after cross-linking of CD4 molecules. The CD$4^+$cross-linking failed to induce effector cell proliferation or the transcription of TNF${\beta}$ Upregulation of TNF${\beta}$ was induced by incubating the antibody activated effector cells with BHV-1 infected D17 target cells for 10 h. Anti-TNF${\beta}$ antibody partially abolished (13-44%) the direct effector cell-mediated antiviral cytotoxicity. However, this antibody neutralized 70 to 100% of antiviral activity of effector and target cell culture supernatants against BHV-1 infected D17 cells. The inhibition level of the antiviral activity by the antibody was dependent on the effector and target cell ratio. These results support the hypothesis that increased p$56^ICK enzyme activity in effector cells transduces a signal critical for effector cell recognition of viral glycoproteins expressed on the target cells. Following target cell recognition, lytic cytokines known to participate in target cell killing were produced. A better understanding of the killing activity displayed by CD$4^+$T lymphocytes following surface receptor cross-linking will provide insight into the mechanisms of cytotoxic activity directed toward virally-infected cells.T cells. The killing activity of antibody activated CD$4^+$T cells was completely blocked by herbimycin A, a protein tyrosine kinase (PTK) inhibitor, but not by bisindolylamaleimide, a protein kinase C (PKC) inhibitor. Herbimycin A treated human or bovine peripheral blood CD4T cells lacked PTK activity and failed to kill virally infected target cells even after cross-linking of CD4molecules. The CD4 cross-linking failed to induce effector cell proliferation or the transcription of TNF$\beta$. Upregulation of TNF$\beta$ was induced by incubating the antibody activated effector cells with BHV-1 infected D17 target cells for 10 h. Anti-TNF$\beta$ antibody partially abolished (13-44%) the direct effector cell-mediated antiviral cytotoxicity. However, this antibody neutralized 70 to 100% of antiviral activity of effector and target cell culture supernatants against BHV-1 infected D17 cells. The inhibition level of the antiviral activity by the antibody was dependent on the effector and target cell ratio. These results support the hypothesis that increased $56^ICK enzyme activity in effector cells transduces a signal critical for effector cell recognition of viral glycoproteins expressed on the target cells. Following target cell recognition, lytic cytokines known to participate in target cell killing were produced. A better understanding of the killing activity displayed by CD$4^+$T lymphocytes following surface receptor cross-linking will provide insight into the mechanisms of cytotoxic activity directed toward virally-infected cells.

• Journal of Life Science
• /
• v.19 no.8
• /
• pp.1170-1176
• /
• 2009

Porcine reproductive and respiratory syndrome virus (PRRSV) has plagued pig populations worldwide causing severe economical impacts. In order to establish effective strategies for prevention of PRRS, infection patterns on the herd level are primarily evaluated. In the present study, therefore, serological and virological analyses were conducted in 20 pig farms suffering from PRRS. Seroprevalence levels in each farm were grouped into 3 patterns: SN (Stable sow groups/Not infected piglet groups, SI (Stable sow groups and Infected piglet groups), and UI (Unstable sow groups and Infected piglet groups). The rates of each serological pattern were 15% (n=3), 10% (n=2), and 75% (n=15), respectively. In addition, the pattern analysis was extended to virological monitoring on the same farms that further included suckling pig groups. As a result, the infection pattern was classified into 4 categories: SNI (Stable sow groups/Not infected suckler groups/Infected piglet groups), SII (Stable sow groups/Infected suckler groups/Infected piglet groups), UNI (Unstable sow groups/Not infected suckler groups/Infected piglet groups), and UII (Unstable sow groups/Infected suckler groups/Infected piglet groups). The rates of each viroprevalence were estimated at 50% (n=10), 30% (n=6), 10% (n=2), and 10% (n=2), respectively. PRRSV viroprevalence results of suckling pig groups revealed that 8 farms were considered virus positive. In 2 farms among these farms, PRRSV appeared to be transmitted vertically to suckling piglets from their sows. In contrast, piglet-to-piglet horizontal transmission of PRRSV seemed to occur in sucking herds of the remaining farms. Thus, this virological analysis on suckling piglets will provide useful information to understand PRRSV transmission routes during the suckling period and to improve a PRRS control programs. Our seroprevalence and viroprevalence data found that infection patterns between sow and piglet groups are not always coincident in the same farm. Remarkably, 15 farms belonging to the UI seroprevalence pattern showed four distinct viroprevalence patterns (SNI; 7, SII; 4, UNI; 2 and UII; 2). Among these farms, 11 farms with unstable seroprevalence sow groups were further identified as the stable viroprevalence pattern. These results indicated that despite the absence of typical seroconversion, PRRSV infection was detected in several farms, implying the limitation of serological analysis. Taken together, our data strongly suggests that both seroprevalence and viroprevalence should be determined in parallel so that a PRRS control strategies can be efficiently developed on a farm level.

• Parasites, Hosts and Diseases
• /
• v.50 no.1
• /
• pp.89-93
• /
• 2012

$Neodiplostomum$ $seoulense$ (Digenea: Neodiplostomidae) is an intestinal trematode that can cause severe mucosal pathology in the small intestines of mice and even mortality of the infected mice within 28 days after infection. We observed neuronal growth associated protein-43 (GAP-43) expression in the myenteric plexus of the small intestinal wall of $N.$ $seoulense$-infected mice until day 35 post-infection (PI). BALB/c mice were infected with 200 or 500 $N.$ $seoulense$ metacercariae isolated from naturally infected snakes and were killed every 7 days for immunohistochemical demonstration of GAP-43 in the small intestines. $N.$ $seoulense$-infected mice showed remarkable dilatation of intestinal loops compared with control mice through days 7-28 PI. Conversely, GAP-43 expression in the mucosal myenteric plexus was markedly ($P$<0.05) reduced in the small intestines of $N.$ $seoulense$-infected mice during days 7-28 PI and was slightly normalized at day 35 PI. From this study, it is evident that neuronal damage occurs in the intestinal mucosa of $N.$ $seoulense$-infected mice. However, the correlation between intestinal pathology, including the loop dilatation, and depressed GAP-43 expression remains to be elucidated.

• Asian Pacific Journal of Cancer Prevention
• /
• v.15 no.22
• /
• pp.9905-9908
• /
• 2014

Background: Helicobacter pylori (H. pylori) is the most common chronic infectious agent in the stomach. Most importantly, it may lead to atrophy, metaplasia and cancer. The aim of this study was to investigate the incidence of H. pylori infection and to detect early mucosal changes that may lead to malignant degeneration in children. Materials and Methods: Children who underwent upper gastrointestinal endoscopy were included. Familial history of gastric cancer was noted. Endoscopic examinations were performed by a single pediatric gastroenterologist. A minimum of three biopsy samples were collected during endoscopy. The patients were accepted as H. pylori infected if results of biopsies and rapid urease test were both positive. Biopsies were evaluated for the presence and degree of chronic inflammation, the activity and severity of gastritis, glandular atrophy and intestinal metaplasia. Results: A total of 750 children (388 boys, 362 girls) were evaluated in our study, with a mean age of 10.1 years. A total of 390 patients (52%) were found to be infected with H. pylori. Among the H. pylori infected patients, 289 (74%) were diagnosed to have chronic superficial gastritis, 24 (6.2%) had gastric atrophy. Most strikingly, intestinal metaplasia was observed in 11 children, all were in the H. pylori positive group. There was no difference in the mean of age, gender and socioeconomic class between H. pylori infected and non-infected groups. The frequency of gastric cancer in family members (4 in number) was higher in patients with H. pylori infection. No gastric cancer case was reported from the parents of non-infected children. The worst biopsy parameters (atropy and metaplasia) were improved after H. pylori eradication on control endoscopy. Conclusions: The current study shows a higher prevalence of familial history of gastric cancer in H. pylori infected children. Intestinal metaplasia was also higher in the infected children. Eradication of H. pylori infection for this risk group may prevent subsequent development of gastric cancer.

• Journal of Fisheries and Marine Sciences Education
• /
• v.28 no.3
• /
• pp.653-660
• /
• 2016

Snakehead, Channa argus were intraperitoneally infected with Nocardia seriolae. at the concentrations of $1.5{\times}10^7cfu/m{\ell}$ or $1.5{\times}10^8cfu/m{\ell}$. The infected fish were kept in aquaria at $25^{\circ}C$ and $30^{\circ}C$ for 3 weeks. Clinical signs and mortality were monitored daily to evaluate the virulence. All artificially infected fish showed the same clinical sign found in naturally infected fish. All the fish infected with $1.5{\times}10^8cfu/m{\ell}$ of N. seriolae died within 24days. N. seriolae showed higher virulence to snakehead at the temperature $30^{\circ}C$. Internal lesions such as whitish nodules in the infected internal organs were not correlated with mortality but some degenerative changes were observed in all the infected organs within a week. Whitish nodules in the infected organs which are the typical character in nocardial infection was initially found at two weeks after the artificial infection in snakehead.

• Research in Plant Disease
• /
• v.9 no.1
• /
• pp.52-56
• /
• 2003

It was conducted to investigate the effect of rice downy mildew (RDM) infection to plant growth and yield components in water seeding stage, and to screen of varietal resistance to downy mildew. Being infected by rice downy mildew, chlorotic spot appeared in the leaf and leaf length was shortened. As the infected rice was growing, internode was not elongated properly and was deformed, and then panicle was not arised or mal-formed. Plant height of infected rice was shortened at all growth stage, and while the number of tillers of infected rice was more decreased than that of healthy plant before maximum tillering stage, and that of infected rice was more increased after heading stage. While the number of internode of infected tiller was much increased than that of healthy tiller internode length of infected tiller was shorter. As the rice infected by RDM severely, the number of panicles per square meter and ripening of rice was more decreased and yield of rice was extremely much decreased. As result of the varietal resistance screening with rice seedling, Geyh-wabyeo and Donjinbyeo were resistant varieties to downy mildew.

• The Korean Journal of Mycology
• /
• v.49 no.4
• /
• pp.469-476
• /
• 2021

Tricholoma matsutake is commercially important wild edible mushroom. The only method for cultivation of T. matsutake has been to use matsutake-infected pine trees. In this study, twenty-one fruiting bodies were collected from the matsutake-infected pine trees in the Hongcheon experimental site in 2020. The fruiting bodies from the existing production area of matsutake-infected pine tree and from its transplantation site were found to be identical through monitoring and analysis of 13 microsatellite markers. Transplanted matsutake-infected pine trees succeeded in fairy-ring formation and matsutake fruiting in 2010 and 2017 to 2020. In conclusion, the matsutake mycelium of transplanted matsutake-infected pine tree originates from the existing matsutake-infected pine tree production.

• Ocean and Polar Research
• /
• v.44 no.4
• /
• pp.319-329
• /
• 2022

The paramyxean parasite Marteilioides chungmuensis infects the cytoplasm of the eggs of Pacific oysters Crassostrea gigas , resulting in spawning failure of the infected females. Such infected eggs appear as bump-like nodules on the body in late fall when most of the uninfected females complete spawning. In this study, we estimated the quantity of the infected eggs using an enzyme-linked immunosorbent assay (ELISA), which is destroyed by M. chungmuensis parasitism. In December, the infected oysters collected from Tongyoung on the south coast exhibited numerous yellowish bump-like nodules as signs of infection. In histology, the infected oysters exhibited mature eggs in the follicle, which were heavily infiltrated by hemocytes. ELISA indicated that the infected egg mass accounted for 7.52±5.50 percent of the body weight, suggesting the ovarian parasite causes substantial reproductive loss. Histology also indicated that the infected oysters are in a poor nutritional condition, as the digestive gland atrophy (DGA) level is comparatively higher than the uninfected oyster. The total carbohydrate contents in the infected oysters (108.68±44.41 mg/g dry wt) were significantly lower than in uninfected oysters (269.76±50.97 mg/g dry wt), suggesting that M. chungmuensis parasitism also affected the energy storage capacity of the host during the resting stage.

• Toxicological Research
• /
• v.11 no.2
• /
• pp.289-294
• /
• 1995

This study was designed to observe the effect of tohiene pretreatment on leukocyte variation in whole blood and the oxygen free radical generating, scavenging enzyme activities in neutrophil of bacteria infected rats. Toluene was administered 7 times intraperitoneally at levels of 9.45 mM/kg body weight to the rats and then infected with S. aureus $2\times10^7$ cfu/ml. The toluene treated-rats showed the significantly decreased numbers of lymphocyte and monocytes, but the similiar numbers of neutrophils with the control. Furthermore the increased neutrophils in blood of bacteria infected rats were reduced by the toluene pretreatment. Concomitantly the increased activities of xanthine oxidase and superoxide dismutase in neutrophil of bacteria infected rats were also decreased by the toluene pretreatment. On the other hand, injection of benzaldehyde to rats also led to similiar results in the count of leukocytes, xanthine oxidase and superoxide dismutase activities of neutrophil with those of toluene treated rats. These data suggest that toluene and its intermediate metabolite, benzaldehyde influence on the phagocytosis and defence mechanism of neutrophil.

• Biomedical Science Letters
• /
• v.19 no.2
• /
• pp.142-146
• /
• 2013

Enterotoxigenic Bacteroides fragilis (ETBF) causes inflammatory diarrhea in humans and animals and is also implicated in colorectal cancer. ETBF-infected mice exhibit a prominent large intestinal inflammation characterized by neutrophil infiltration and induction of the Th17 response. In this study, we examined differences in the secreted cytokine profile of the cecum and proximal colon of ETBF-infected mice using an antibody array. Of the cytokines examined, we found that the cecal tissues from ETBF-infected mice secreted elevated levels of G-CSF, IL-6, IL-17 and LIX compared to non-toxigenic Bacteroides fragilis (NTBF) and Mock infected mice. The proximal colon tissues from ETBF-infected mice secreted higher levels of G-CSF, IL-6, KC, LIX, MIP-1g and MCP-1. This study demonstrates that the cecum and colon should be considered separately when assays are used to determine immune responsiveness to enteric infections.